The overall objectives of the research proposed are to characterize the human autologous mixed lymphocyte reaction (MLR) and to examine the autologous MLR as a mechanism of immune surveillance. Specifically, the lymphoid populations which proliferate in the autologous MLF will be characterized with respect to their T-cell subset and their antigenic specificity. Immune effector functions, (suppressor, helper and cytotoxic activity) generated during the autologous MLR will also be determined. Finally, autologous mixed lymphocyte reactivity and the capacity to generate anti-leukemic CTL will be measured in patients with acute myeloblastic and acute lymphoblastic leukemia.